A semiconductor laser typically comprises a body of semiconductor material including a cavity region between cladding regions of opposite conductivity type. To increase the output power, the cavity region typically includes a guide layer in addition to the active layer so that light generated in the active layer propagates in both the active and guide layers thereby forming a larger beam at the emitting facet of the body. The cavity region also restricts oscillation in the transverse direction, the direction perpendicular to the plane of the layers, to the fundamental optical mode. In the lateral direction, the direction in the plane of the cavity region and perpendicular to the direction of light propagation, structural variations in the body produce an optical waveguide which in turn restricts the oscillation to the fundamental lateral optical mode. Lasers incorporating transverse and lateral waveguides, such as those disclosed by Botez in U.S. Pat. No. 4,347,486, incorporated herein by reference, may have output powers in excess of 40 milliwatts in the fundamental lateral and transverse mode. To further increase the output power monolithic arrays of phase-locked lasers which operate with output powers up to about 80 milliwatts have been fabricated. However, the output radiation pattern of these devices typically comprises two lobes equally spaced in angle about the normal to the emitting end face of the array. This output pattern is undesirable from a systems viewpoint because only about one half of the emitted light can be used in systems with beam forming optics, thereby negating the advantage of these arrays. Thus it would be desirable to have a phase-locked laser array in which the radiation pattern consisted primarily of a single lobe, preferably normal to the emitting end face of the array.